When a terminal performs a data service, a network needs to control policy information of the data service, so that services with corresponding QoS (Quality of Service) may be performed for different data services. In the next generation SAE (System Architecture Evolution) network, decision may be made on the policy information required by a data service requested by a terminal via a PCRF (Policy Control and Charging Rules Function). FIG. 1 shows an architecture of an SAE network based on non-roaming scenario, including: a UE (User Equipment) (such as a mobile phone), which functions as a terminal; IMS (IP Multimedia Subsystem) 14; AF (Application Function) 13, which functions as a service server; PCRF 12; RAN (Radio Access Network) 11; and MME (Mobility Management Entity)/UPE (User Plane Entity)/IASA (Inter AS Anchor), and so on.
The IASA is used for connecting an external data network, such as an IMS. The UPE is used between RAN 11 and IASA, for establishing a data connection for the UE and transferring data. The MME is used for managing location information of a user plane device in RAN. The PCRF 12 obtains, from AF 13, the data service information requested by a UE, and makes decision on the policy information required by the data service (for example, QoS and charging rules required by the data service), then delivers the decision result to MME/UPE/IASA, and policy information such as related charge may also be preconfigured on PCRF 12, so that the MME/UPE/IASA may initiatively request PCRF 12 to deliver the policy information.
When a terminal wants to perform a data service on the SAE network, the terminal first accesses the network via RAN 11, then establishes a connection with the IASA via MME/UPE, and then establishes a connection between RAN 11 and IMS 14 via MME/UPE and the IASA. The terminal sends a service request to IMS 14 to inform IMS 14 of the requested service, IMS 14 informs PCRF 12 of the service information required by the terminal via AF 13, and PCRF 12 determines which policy information is needed by the service, and delivers the policy information to the MME/UPE/IASA; and then the MME/UPE/IASA executes the policy information.
The case, in which the network controls the policy information of a data service when the terminal requests the data service in local home network, has been described above. The case, in which the network controls the policy information of the data service after the terminal roams to a VPLMN (Visited PLMN), will be introduced.
FIG. 2 shows architecture of an SAE network in roaming scenario, which includes a VPLMN and an HPLMN (Home PLMN), and the HPLMN refers to the operator network to which a user subscribes. The VPLMN includes vPCRF (Visited Policy Control and Charging Rules Function) 21 and MME/UPE/vIASA 24; the HPLMN includes IMS 26, AF 27, hPCRF (Home Policy and Charging Enforcement Function) 22 and hIASA (Home Inter AS Anchor) 25.
When a terminal roams to a visited network and wants to carry out a data service, the terminal visits via the VPLMN and establishes a connection with hIASA 25 in the HPLMN via MME/UPE/vIASA 24 in the VPLMN, and establishes a connection with IMS 26 via hIASA 25. When the connection is established successfully, the terminal sends a request data service to IMS 26, and IMS 26 sends the service data requested by the terminal to hPCRF 22 via AF 27. The hPCRF 22 decides which policy information should be allocated to the service data, and then delivers the decision result to vPCRF 21 initiatively, or waits for vPCRF 21 to acquire the decision result. Finally, vPCRF 21 transparently transmits the obtained decision result to MME/UPE/vIASA 24, and the MME/UPE/vIASA 24 executes the policy information of the decision result.
The inventor finds that there exist at least the following problems in the prior art: the conventional method for controlling policy information required by a service via the network is only applicable for the case in which some policy information of the VPLMN operator is not configured in vPCRF 21, or the case in which some policy information of the VPLMN operator is configured in vPCRF 21 and the policy information is same as corresponding policy obtained by vPCRF 21 from hPCRF 22. For the case in which some policy information of the VPLMN operator is configured in vPCRF 21 and the policy information is different from the corresponding policy obtained by vPCRF 21 from hPCRF 22 or the corresponding policy delivered to vPCRF 21 by hPCRF 22 initiatively, no related processing method exists at present.